Study of the drug resistance and genetic mutations of Candida albicans infecting patients with vaginitis

Objectives To isolate Candida albicans infecting patients with vaginitis and to determine its drug resistance and the state of genetic mutations in drug-resistant strains in order to guide the rational drug use in clinical settings.Methods Clinical isolates of C.albicans were determined to be drug-resistant strains or drug-sensitive strains,and a susceptibility test was again performed after passaging to verify drug resistance.Genomic DNA was extracted and detected using electrophoresis,and the ERG11 gene was amplified and sequenced using PCR. Results The susceptibility test indicated that the MIC of fluconazole for C.albicans GZ16 was 64μg/ml after passaging;GZ16was deemed to be a drugresistant strain.The MIC of fluconazole for C.albicans SC5314 was 2ug/ml,and SC5314 was deemed to be a drug-sensitive strain.Genomic DNA electrophoresis revealed that target bands for GZ16 and SC5314were in the same location.Sequencing of the ERG11 gene revealed that C.albicans GZ16 had 2point mutations,G487 Tand T916C,while C.albicans SC5314 had 8point mutations,All67 G,A1587G,T462 A,T495A,A504 G,A530C,C558 T,and C805 T.SC5314also had missense mutations of amino acids,including F105L(T462A),D116E(T495A),and K128T(A530C). Conclusion Some of the C.albicans strains isolated from patients with vaginitis were resistant to fluconazole and they had point mutations in the ERG11gene(G487Tand T916C).These mutations might be related to the resistance of C.albicans to fluconazole.